Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: VLF: VO1NA in Todmorden on 8270 Hz - also in Amberg?

To: [email protected]
Subject: Re: VLF: VO1NA in Todmorden on 8270 Hz - also in Amberg?
From: Paul Nicholson <[email protected]>
Date: Thu, 9 Nov 2017 11:34:50 +0000
Dkim-signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:To:Subject:Sender:Reply-To:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=o7POWfVCxgUiR+NWJpNmAT2gWXfsLQQNlJkYqBZkLkY=; b=gJltQFLKTFj5KfT1CutodNdOk+ CPAuuS0AoRzDwQ29Z/1SwCz2F1s8ou0PljgF8R1vLLQbjWCm/NvaomlUbcM9vGOtMOXz208zd2B0K 0kmDIt5CGq0S3e+2IBncQ1E2G2rl72mhKhohlNnKKuR/WLg64u/b0nR0uyzXVMo3Q2iQ=;
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0

> cat msg7 |
>   ebnaut -et -N8 -k20 -p16K21A |
>   sudo ebkey -S21 -m rp,gpio=23 -T '20171106 2200'

Decoded 'EINSTEIN' from the overnight 8th/9th transmission.

Eb/N0 = -0.5 dB, constant reference phase, BER 41.1 %

Symbol error map http://abelian.org/vlf/tmp/171109a.gif

  Night   Eb/N0    Phase   S/N
  6/7th  -20.0 dB          < -48 dB in 1Hz
  7/8th  -3.7 dB    97.6  -31.79 dB in 1Hz  (E+H)
  8/9th  -0.5 dB   128.8  -28.63 dB in 1Hz  (E+H)

  8/9th  -3.2 dB   131.1  H-field only
  8/9th  -2.3 dB   126.7  E-field only

Nothing at all from the 1st night and clearly something
broke during the 2nd night.

After a full phase search I got a slight improvement to -0.4 dB
with phase pattern -150,-150,180,180, which means the signal
phase is lagging a little (on average) after about 02:00.

This decode is about at the limit for the transmitter power and
message duration.  Looking at the error map, we might be able to
use a longer message but will probably only manage 9 chars max.

--
Paul Nicholson
--

<Prev in Thread] Current Thread [Next in Thread>